Hi! To start off, I shall give a short introduction.
Basically, this guide is based on my personal knowledge, research & help from friends.
The following information maybe not be 100% accurate or up to date. (P.S I'm not a pro in COL yet =P)
So, if you spot any mistakes or there's anything that you can update me with, please feel free to let me know and I will update them! =D

Resources
The first thing we will be talking about shall be resources. As without resources, there won't be development in the game.Gold

The only mining resource in this game currently is only gold.
Players can use gold to upgrade all the buildings or walls, or using it for resource raid as well as revenge on others for trophy where we will be talking more about that later on as we proceed.

Ways of getting gold
1. Gold Mine, the most basic way is to collect gold every hour. It's probably one of the slowest advancement way if you are those that use to grinding or have many builders. Well, that to be said, it can help you a lot when you're not online (Working or Sleeping) to accumulate some gold so that you won't lack behind too much in game.
2. Resource Raid, your best and only way to get gold super fast. Each battle and scan for base cost 50gold or more (depends on your TH level) but you can get back many times more if you got the right base that leaves a super gold mine for you!
3. Dungeon, your secondary way to win gold, but dungeon will get harder and harder, to the stage where you will have a very hard time to get 3 stars. It will come to a time where you have to grind back previous stages, which cost you 1 chances which will recharge every 2hours. It may not be the best way to earn gold, but the chest is definitely worthy.
4. Quests, you may think that quests can sometimes be tedious or long to complete, but the reward gets higher each time and certainly, you will love quest a lot. You can get gold by advancing in dungeon, at the same time completing the quest for the dungeon section which gives you both gold and experience.

Souls
Souls are resources you can use for upgrading your Mercenary or activating armours for your buildings.
They are very important because leveling up your Mercenary is crucial in attacking other player's base!

Ways of getting souls
1. Lords League, you will get souls every hour, and how much souls you get depends on your ranking in the league.
By raiding a base in Lords League, not only you will get trophies, you will get some souls as well.

2. Dungeons, it rewards you a certain amount of souls the first time you got a 3 stars from the stage. Subsequently, the chest you get from dungeons rewards you with souls as well.

4. The Cat's Meow, a small mini game where you consume a mug to get 1000 souls. By spending Gems in it, you can multiply the amount you get by playing Rock, Scisscor & Paper which cost 150Gems each play. It's a better choice to save mugs for rings instead because souls aren't that hard to get as rings are!

Rings
Probably one of the hardest thing to earn in game. Rings are use to level up your hero skills, or you can use it to buy Rare or Epic Heroes in the shop.

Ways of getting rings
1.The Cat's Meow, probably one of the easiest way to get rings. Each mug gives you 10 rings, and you can always multiply it with gems! (Mugs can be obtained through dungeons only)

2.Dungeons, the best way to collect mugs! More mugs, more rings! Sometimes the chest gives you rings as well, although it's not a lot, take it as extra rewards!

3.Quest, gives you almost all the rewards! Including rings as well! You can either level up your troops, heroes, skills or gaining trophies to complete quests that rewards you with rings! It's not gonna be fast but take it as your hard work paid off!

4.Lucky Spin, it may give you 5 rings, or it can award you with 100! You can get a free lucky spin when your Luck Bar is 100%. However, in order to get 100%, you need to recruit as much hero as you can! This can be fast for some players, or it can be real slow for others.

You can always continue spinning if you use gems!
(Note: The amount of rings in the center is random, lucky ones may get 10 rings X ??? for that spin!)

Battles
The next thing I am going to talk about is COL2's attack system! COL2 has a system that gives the player 3 different mode of battles!

Lords League
Time for some leaderboard rankings! In this mode, players will be given 10 chances each day to choose to attack a random player's base, which rewards you with trophies and souls. This mode will not affect the opponent's resources! However, it will affect the amount of trophies which leads to the players' personal ranking. Not to mention, this mode will gives players a certain amount of souls every hour, depend on the players' personal ranking in the leaderboard!

Alternatively, you can always re-roll your opponents with 10 gems, if you have no means of attacking any of the 5 players! =)
(Note : In order to get the full amount of trophies shown, you will need to get 3 stars victory)
And of cause, losing the battle, cause you to lose your own trophies as well! So be sure to choose the base you're confident in!

Revenge system
Frustrated? Players are taking trophies away from you while you're sleeping? Don't worry! In COL2, there's a revenge system for you to take back your trophies! It may cost you more golds each time you take revenge. First revenge will cost you 10k gold, and subsequently 20k, 40k, 80k.... Well, trophies are definitely worth spending your gold for! So, just take revenge and show them who's boss! You just need at least 1 star for revenge to win all the trophies! (Note : Revenge may lose trophies if you didn't manage to get a victory as well =P)

Resource Raid
Resources!!! The random matching of player's base for players to grab each others resources! As I mentioned, this is probably the battle most players would be playing most of the time, because it has unlimited tries as long as you have the few hundreds gold to spare! (Note : The gold fee increases depends on your Town Hall level)
After destroying the opponent's base to a certain percentage, the opponents will get shield for some time. During this time, the opponent's base will be protected from resource raid match up, but the shield does not affect Lords League battle.

Dungeons
The single player mode for players to pass through stage by stage which gets tougher when players advance. Players have 5 chances to lose in a dungeon stage, or you can consume the chances by replaying the previous stage for farming chest purpose. The chances will replenish every 2 hours for each chance. In order to get full reward on each stage, you will need to get a 3 stars victory! Not to mention, the chest rewards gets better every 5 stages cleared, so don't be surprise if you get something awesome in it when you advance! ^^